A clonal strain of Pseudomonas aeruginosa (PA) was isolated in 1999 at the Royal Children's Hospital, Melbourne, Australia, after five unrelated children with cystic fibrosis (CF) died from severe lung disease aged <5 yrs. Subsequently, more than half of the patients in the clinic with PA were found to harbour this strain, and segregation measures were instituted at the hospital to prevent further spread. The aim of this study was to assess CF parent and patient responses to the segregation measures to determine overall support. A questionnaire was sent out to the families of 291 CF children treated at the centre. A 65% response rate was obtained. The majority of parents (85%) and patients > or=12 yrs old (63%) were positive about the segregation measures instituted. A total of 11% of parents and 25% of patients were unsure, and 4% of parents and 12% of children gave negative responses. Those who were not happy listed reasons such as concerns about the emotional impact of not socialising with other CF children, inconclusive evidence about person-person spread of infection and feelings of alienation created in the clinic by the separation. In conclusion, the majority of responding cystic fibrosis patients and their families understand and are supportive of infection control measures instituted at the Royal Children's Hospital, Melbourne, Australia.